This invention relates to a hydroelectric power generation equipment comprising a hydraulic turbine and an electric power generator. The electric power generator is driven by the turbine to produce electric power and, more particularly to drive a runner blade drive apparatus of a movable blade water turbine for middle or low head such as a Kaplan turbine, a tubular water turbine, etc. in the hydroelectric power plant.
A movable blade water turbine is provided with a runner blade drive apparatus for optimum adjustment of a blade opening according to water head, and water flow rate at the turbine. A conventional runner blade drive apparatus will be explained utilizing a Kaplan turbine for instance. The Kaplan turbine is connected to an electric power generator so that a turbine shaft is aligned with a generator shaft, whereby the generator is rotated by the turbine to generate electric power. The conventional runner blade drive apparatus comprises two elongated pressurized oil passages and pass through a hole formed in each of the turbine shaft and the generator shaft, and a double action hydraulic cylinder disposed in the runner for actuating the blades through links connecting therebetween, with the pressurized oil being supplied to the cylinder through the passages. The pressurized oil passages are long (some conduits have total length of 20 m), so that conduits defining the passages each are divided axially into 4 or 5 parts and connected by bolts at flange portions thereof to be one conduit. The conduits are arranged coaxially in the holes of the turbine shaft and the generator shaft so that gaps are provided between an outer one of the conduits and the inner walls of the holes of the shafts even between the flange portions of the outer conduit and the inner walls. Each of the lower ends of the conduits are connected to runner-related parts by means of bolt and nut.
Further, the apparatus has a pipe for detecting a runner blade opening. The pipe is inserted in an inner one of the conduits, divided axially into 4 or 5 parts and connected by bolts means at flange portions to comprise one elongated pipe, the opening detection pipe is connected to a runner-related part at a lower end thereof.
The conduits and the opening detection pipe are rotated together with the turbine shaft and the generator shaft at the same angular velocity when the turbine is rotated.
Shaft vibrations can occur in the conduits and the pipe during their rotation. When the shaft vibrations occur, and the outer conduit contacts the inner wall of the hole of the turbine shaft or the generator shaft noise or damage which results due to impinging of the conduit on the inner wall increases, unless the small gap is not sufficiently large.
Further, the lower ends of the conduits and the opening detection pipe are connected to the runner related parts by means of bolt and nut, as mentioned above, when it is necessary to disassemble the turbine and generator to repair it when the conduits or the opening detection pipe have been damaged. Labor and cost required for the repair of the conduits are large.